ls-options

ls -a	      list all files including hidden file starting with '.'
ls --color	colored list [=always/never/auto]
ls -d	      list directories - with ' */'
ls -F	      add one char of */=>@| to enteries
ls -i	      list file's inode index number
ls -l	      list with long format - show permissions
ls -la	    list long format including hidden files
ls -lh	    list long format with readable file size
ls -ls	    list with long format with file size
ls -r	      list in reverse order
ls -R	      list recursively directory tree
ls -s	      list file size
ls -S	      sort by file size
ls -t	sort by time & date
ls -X	sort by extension name